摘要
三电平拓扑结构相对于两电平在性能上有很多优势,但是也存在中点电位不平衡这一固有问题。基于简化的三电平空间矢量脉宽调制(space vector pulse width modulation,SVPWM),提出一种混合式的三电平中点平衡控制策略。该控制策略在低调制度下,根据中点电压偏移情况,结合三相电流,明确重叠区域的扇区选择原则,克服非冗余小矢量造成的中点偏移;高调制度下,充分考虑中矢量对中点偏移的影响,对不同的小三角形设置不同的时间控制因子,实现对中点电位平衡的精细化控制。基于DSP构建三电平逆变器硬件平台,在1140V/500kW三相异步电机和三相电感上完成了相关实验。实验结果验证了该方法可以实现全频率段中点电位的平衡控制。
The three-level topology has a lot of advantages compared with the two-level one, but it also has some problems such as the neutral-point unbalance. This paper proposes a hybrid three-level neutral-point balance control strategy used for the simplified three-level Space Vector Pulse Width Modulation （SVPWM）. The control strategy clearly clarifies sector selection principle based on the neutral-point voltage offset and the three-phase current under the low modulation index condition to overcome the voltage offset caused by non-redundant small vector. In high modulation index condition, it fully considers the impact of the medium vector on the neutral-point voltage offset, sets a different time controlling element for every small triangle to achieve meticulous control of neutral-point, A three-level inverter hardware platform was built based on DSP, and relevant experiments have been done on the 1 140 V/500 kW three-phase induction motor and three- phase inductor. Experimental results verified that the algorithm can achieve neutral-point balance control of a full frequency range.
出处
《中国电机工程学报》
EI
CSCD
北大核心
2013年第24期82-89,13,共8页
Proceedings of the CSEE
基金
北京市科技新星计划资助(2009B01)
北京市属市管高等学校人才强教计划资助项目(PHR201008188)
北京市优秀人才培养项目(2012D005002000009)~~
关键词
三电平
中点平衡
空间矢量脉宽调制
混合式
调制度
three-level
neutral-point balance
space vectorpulse width modulation （SVPWM）
hybrid
modulation index
